To get to Ocracoke by car you need to ride the ferry from either Hatteras, Swan Quarter or Cedar Island.

The Hatteras ferry is free and crossing take about 1 hour.
The Swan Quarter and Cedar Island ferries charge a $15 fee each way and reservations are strongly suggested either online at www.ncdot.gov/ferry, or by calling: 1-800-BYFERRY.
The current ferry schedule for early fall are here:
http://www.ncdot.gov/download/transit/ferry/ferryschedule.pdf
THIS SCHEDULE WILL CHANGE AT THE END OF SEPTEMBER. Please check back at this site for the October-November ferry schedule.
If you have a private small plane, the Ocracoke airport is open during daylight hours.
By your own boat, there is dockage available at the Anchorage Marina and the National Park Service docks.